public async Task <ActionResult> SendTelemetry(string connectionString, string modelId)
        {
            Twin twin = await _helper.SendTelemetry(connectionString, modelId);

            return(Json(twin.ToString()));
        }
        public async Task <ActionResult> ConnectDevice(string connectionString, string modelId)
        {
            Twin twin = await _helper.ConnectDevice(connectionString, modelId);

            return(Json(twin.ToString()));
        }